In many technical applications there is a need for very small valves for gases and/or liquids. Mechanical and/or electromechanical valves are often difficult to miniaturize, and expensive to produce.
As an alternative to mechanical and/or electromechanical valves there are known in the prior art actuators and valves using electrochemical means for the actuation.
One example of an electrochemical actuator is disclosed in U.S. Pat. No. 5,671,905. It comprises an electrolyte solution sealed within a substantially constant volume chamber, having electrical contacts disposed therein such that the electrolyte is in electrical connection with the electrical contacts. Passage of current between the contacts through the electrolyte, separates the electrolyte and or electrode material into its component gas or gases, resulting in an increased pressure within the chamber. This pressure can either act directly upon, or be routed via pneumatic or hydraulic lines, to actuate a diaphragm, move a piston, inflate a bladder, or any other suitable means of converting pressure to motion or displacement.
Another example is disclosed in U.S. Pat. No. 5,038,821. It is an electrochemically actuated control valve which is actuated by an electrochemical prime mover that converts DC electrical energy into compressed gas energy that is then used to produce mechanical work. The mechanical motion of the electrochemical actuator is typically linear motion.
The above mentioned devices are manufactured as separate units requiring separate mounting or integration in the system in which they are to be used. They also comprise a plurality of components that has to be assembled, rendering the manufacture fairly complex and thus costly.
The published patent applications WO 2007/117212, WO 2009/025613 and WO 2009/025614 describe fuel cell technology according to the state of the art.